Electrolytic Carboxylation of Substituted Olefins

ABSTRACT

Olefinic nitriles, esters and amides having hetero-atom containing groups are electrolytically carboxylated.

United States Patent [1 1 [111 3,864,225 Tyssee Feb. 4, 1975 [54] ELECTROLYTIC CARBOXYLATION OF 3,193,478 7/1965 Balzer 204/73 SUBSTITUTED ()LEFINS 3,344,045 9/1967 Neikam 204/59 R 3,344,046 9/1967 Neikam 204/59 R [75] Inventor: Donald Armon Tyssee, St. Louis,

Mo. OTHER PUBLICATIONS B5 and B6 by Tsutsuni et al., Symposium on Electro- [73] Asslgnee' Monsanto Company chem. Conversion of Hydrocarbon-based Raw Materi- [22] Filed: Nov. 17,1972 als, Div. of Pet. Chem. Inc., Chicago, Sept. 13-18,

- 1970, printed by Sauls Lithograph Co., Inc., Washing- [21] Appl. No.. 307,753 ton DC Aug 1970 U.S. R, Primary Examiner .F C Edmundson [51] Int. Cl... C07b 29/06, C07c 51/40, C07c 55/02 [58] Field of Search 204/59 R, 72, 73 R [57] ABSTRACT [56] References Cited Olefinic nitriles, esters and amides having hetero atom UNITED STATES PATENTS containing groups are electrolytically carboxylated.

3,032,489 5/1962 Loveland 204/73 R 1 Claims, 9 Drawings ELECTROLYTIC CARBOXYLATION OF SUBSTITUTED OLEFINS BACKGROUND OF THE INVENTION The present invention relates to the electrolytic car boxylation of certain substituted olefinic nitriles, esters and amides.

Carboxylic esters and derivatives are well known industrial chemicals, having such diverse uses as plasticizers, monomers for the preparation of polyesters by interaction with glycols, etc. It has previously been known that some types of unsaturated compounds are subject to reduction at the cathode and dimerization. It has also been known that when relatively stable reduction intermediates are obtained because of substituents on the olefinic group, as in the case of benzalacetone, the intermediates will react with carbon dioxide to form carboxyl compounds; (see Wawzonek et al J. Electrochem. Soc., Vol III, pages 324 to 328, (l964).

DETAILED DESCRIPTION OF THE INVENTION The course of the reaction of the present invention can be illustrated:

YCRORX YCR=CRX 2(302 l electrolysis C: C02

YCR-(FRX in which the Rs are individually selected from hydrogen. monovalent al phatic radicals, or X, and X is selected from in which R is a monovalent organic radical, and the R"s are individually selected from monovalent organic radicals and hydrogen; and in which Y is an oxy, thio, phosphino, or amino group, e.g. alkoxy, aryloxy, alkylthio, arylthio, alkylamino, alklphosphino, arylamino, arylphosphino, and such general groups are RO R'S R'N RP in which R is defined as above. The heteroatoms are ordinarily directly attached to the olefinic carbon, in which position the electron releasing effect upon the olefinic group is mostpronounced, but it is to be understood that the presently disclosed process is also operative with the heteroatoms in a more remote location, as the heteroatom in remote locations, is less likely to influence the course of the reaction. It should also be noted that Y in the above formula can be present on the same olefinic carbon atom as X, i.e., Y can be either a or ,8 to the nitrile, ester or carboxamido group, and that R in the formula can be Y. Illustrations of some specific Y groups are, for example, methoxy, ethoxy, hexyloxy, decyloxy, methylthio, ethylamino, diethylamino, hexylamino, methylphosphino, diethyphosphino, etc. Aside from the Y groups ordinarily the various organic radicals when present in the reactant will be hydrocarbyl, unless there is some reason for having other groups present, particularly lower hydrocarbyl, such as groups of no more than ten carbon atoms, although longer chains may occasionally be employed for particular purposes. Alkyl, including cycloalkyl, or aryl groups can conveniently be employed. It is also feasible for the heteroatom to constitute part of a heterocyclic compound, employing such groups as piperidino groups, etc.

The carboxyl compounds produced in the present invention can be recovered in the form of free acid, es-

ters or salts. With a fair amount of proton donor in the electrolysis, the product is generally in the form of the free acid, and can be separated by extraction, e.g. with ether, and evaporation of the extracting medium. If the product is in the form of a salt, it can be converted to the free acid by mild acidification, e.g., with dilute min eral acid, and isolated as such. Some products may exhibit a tendency to decarboxylation upon use of stringent conditions such as high temperatures and concentrated strong acids, so care should be exercised in such cases to avoid decarboxylation. In the procedures in which nitriles are employed, it will ordinarily be desirable to avoid conditions known to result in hydrolysis of the nitrile group, such as excessively acid or basic conditions with elevated temperatures. When a nitrile is the starting material, it will generally be desirable to retain the cyano group in the product and to obtain a B-cyanocarboxylic acid, rather than hydrolyze the nitrile group, as such products are less readily available from other sources than are the corresponding succinic acids which are obtained by the hydrolysis. However the present procedure is still to be considered operative even though hydrolysis does result in the production of succinic acid. With respect to the olefinic esters and amides, it will be noted that such groups are also subject to hydrolysis and the foregoing also applies to reactions involving such compounds, although conversion from ester to free acid form may often be comtemplated for a particular product. If it is desired, the carboxylated products can be converted to ester form by usual esterification procedures, e.g., by treatment with methyl iodide or dimethyl sulfate. The ester forms are amenable to separation by extraction procedures. The products may at times be found in salt form because of the presence of salts in the electrolysis, but, in any event, can be converted to salt form by treatment with bases, and salts can frequently be isolated by aqueous solvent extraction. The decarboxylation products which may be obtained in the process are, in general useful, but their desirability as products in a particular reaction may depend upon the modifications over the starting reactant; for example, a process which effects a dicarboxylation, followed by mono-decarboxylation, may be suitable for producing the resulting acid.

The degree to which dimerization occurs is in general dependent upon competitive reactions between the starting olefin and its reduction products, carbon dioxide, and any proton donors which may be present in the reaction mixture. Hence, the process is subject to direction to some extent by regulation of the olefin and carbon dioxide concentrations. The rate at which the reduction products are further reduced is also influential, and may provide an additional control. For example, if the reaction shows a single electron uptake polargraphically in the presence of CO at given potential, the potential can be controlled to provide for only the first electron uptake, and dimer products will generally be obtained in preference to products resulting from addition of a second electron to the initial reduction intermediate.

If the potential is controlled to cause the uptake of two electrons, the concentration factors are then influential and the process can be directed toward production of carboxylated monomer.

Oleflnic reactants to which the present process is applicable include, for example, 3-ethoxyacrylonitrile, ethyl 3-ethoxyacrylate, methyl 3-methylthiomethacrylate, 3-diethylaminoacrylonitrile, ethyl 3-phenoxycrotonate, phenyl 3-pentoxyacrylate, ethylphosphinoacrylonitrile, etc. The process results in production ofa product corresponding to the reactant, but with one or more carboxyl groups substituted on the carbon atoms of the double bond, with the bond becoming saturated. When there is only monocarboxylation, the substitution will generally be on the caron atom beta to a nitrile, carboxyl, or amido group of the reactant. If desired, the degree of monoand dicarboxylation obtained can be influenced by carefully controlling the amount of proton donor present in the electrolyte, as taught in my corresponding application Ser. No. 306,227, filed Nov. 13, l972. The carboxylation may also be acompanied by some dimerization, as discussed herein, and further described in my copending application Ser. No. 317,345 filed Dec. 21, 1972.

The present process is believed to involve reduction of the olefinic reactant and subequent reaction with carbon dioxide. The types of activated olefins utilized herein are known to be subject to reduction to form v radical anions as transitory intermediates. The intermediates which are formed are relatively short-lived and differ in this respect from other radical anions which are reactable with carbon dioxide. For example, phenyl or other aromatic substitutents on an oleflnic carbon atom are known to stabilize radical anions obtained by reduction of such olefins. In the present process it has been found unnecessary to have long-lived reduction intermediates, and aromatic substituents are not necessary in order to obtain carboxylation with the type of activated olefins employed herein. Aromatic substituents on carbon atoms other than those of the olefinic group will not in general affect the aliphatic character of the olefinic reactants in that the intermediates obtained can still be very short-lived and transitory, i.e., the aliphatic olefinic acid derivatives employed herein will not have any aryl groups in position to form conjugated double bond systems with the olefinic group.

The electrolysis is carried out by passing an electric current through the olefinic compound in contact with a cathode and in the presence of carbon dioxide. The olefinic compound or medium in which it is employed must have sufficient conductivity to conduct the electrolysis current. It is preferable from an economic viewpont not to have too high a resistance. The required conductivity is generally achieved by employing common supporting electrolytes, such as electrolyte salts of sufficiently negative discharge potentials. Water when employed as a proton donor also contributes to conductivity.

The present reaction is preferably effected in the presence of a solvent for the olefin and the electrolyte. The electrolyte salts may not be readily soluble in the olefins. In addition the solvents are useful as diluents in order to obtain desired ratios of reactants. Carbon dioxide at atmospheric pressure has only limited solubility in most of the oleflns and solvents employed herein. lf extensive dimerization or other oligomerization reactions are to be avoided, it is desirable not to have too great an excess of the olefinic reactant over the carbon dioxide. For example, the olefin concentration can be regulated so as not to be more than ten times the carbon dioxide concentration on a molar basis. To achieve this in reactions at atmospheric pressure the olefin concentration would ordinarily be no greater than one molar. Often it is convenienct to add the olefin to the reaction medium in increments, or gradually as utilized in the reaction. In the event dimerization as well as carboxylation is desired, it may be disirable to utilize higher concentrations of olefins, even up to the complete absence of a solvent diluent.

It will generally be desirable for the solvents to have a fairly high dielectric constant in order to lower electrical resistance. Of course, the choice and concentration of electrolyte salts can also be used to lower electrical resistance. Solvents desirable for use herein include, for example, dimethylformade, acetonitrile, hexamethylphosphoramide. dimethylsulfoxide, etc. ln general it is desirable to employ a solvent with a dielectric constant of at least 25, and preferably of at least 50. Many of the useful solvents can be characterized as aprotic, and such solvents can suitably be utilized, particularly those of dipolar character which exhibit high dielectric constants. As discussed herein, the protonation or lack of protonation, of intermediates has an effect upon the products produced in the present invention. Protonation can be utilized to direct the process toward particular products. Thus it is not essential to use aprotic solvents. However such solvents are convenient for controlling the protondonating character of the electrolysis medium, as small amounts of water or other proton donors can be added to such solvents to achieve desired results.

While protons can be utilized for controlling the degree of carboxylation, the presence of protons is not necessary for the purpose of avoiding polymerization or similar side reactions. The extent of dimerization and similar reactions is influenced by the concentration of reactants. in particular the relative concentration of carbon dioxide determines whether the olefinic intermediates react with carbon dioxide, or with other olefinic molecules. Since the degree of dimerization can be influenced by the relative carbon dioxide concentration, it is not generally necessary to use water for this purpose. Control of the cathode potential can also be used in some cases to influence the process toward or away from dimerization.

in the present process it is generally desirable to have the electrolyte, olefinic reactant and solvent in a fairly homogeneous dispersion. A true solution is not required as, for example, many quaternary ammonium salt solutions may, in some respects, be dispersions rather than true solutions. Thus the present invention may use emulsions as well as true solutions. Moreover in emulsions or media having more than one phase, electrolyses can occur in a solution of the components in one of the phases.

With the electrolyte and solvent materials usually employed, the catholyte will generally be approximately neutral, so far as acidity-basicity is concerned. and no particular provisions are necessary to regulate this parameter. However, it will usually be desirable to operate under near neutral conditions in order to avoid possibly promoting hydrolytic or other side reactions, or protonation of intermediates. Solubility and stability considerations with respect to the olefins and carboxylated products may also be relevant to selection of desirable pH values. In long term continuous reactions with re-use of catholyte media, it may be desirable to use buffers or to adjust pH periodically to desired values.

In carrying out the present process, a supporting electrolyte is generally used to enhance conductivity. With some combinations of activated olefins and solvents, an additional electrolyte may not actually be necessary, but in pratice a supporting electrolyte is utilized in the present invention. A supporting electrolyte, as understood by those in the art, is an electrolyte capable of carrying current but not discharging under the electrolysis conditions. In the present invention, this primarily concerns discharge at the cathode, as the de sired reaction occurs at the cathode. Thus the electrolytes employed will generally have cations of more negative cathodic discharge potentials than the discharge potential of the olefinic compound. An electrolyte with a similar or slightly lower discharge potential than the olefinic compound may be operative to some extent, but yields and current efficiency are adversely affected, so it is generally desirable to avoid any substantial discharge of the electrolyte salt during the electrolysis. It will be recognized that discharge potentials will vary with cathode materials and their surface condition, and various materials in the electrolysis medium, and it is only necessary to have an effective reduction of the olefinic compound under the conditions of the electrolysis, and some salts may be effective supporting electrolytes under such conditions even though nominally of less negative discharge potential than the olefin employed.

ln general any supporting electrolyte salts can be utilized in effecting the present process, with due consideration to having conditions suitable for the discharge ofthe olefinic compound involved. The term salt is employed in its generally recognized sense to indicate a compound composed of a cation and an anion, such as produced by reaction of an acid with a base. The salts can be organic, or inorganic, or mixtures of such, and composed of simple cations and anions, or very large complex cations and anions. Amine and quaternary ammonium salts are generally suitable for use herein, as such salts generally have very negative discharge potentials. Certain salts of alkali and alkaline earth metals can also be employed to some extend, although more consideration will have to be given to a proper combination of olefin and salt in order to achieve a discharge. Among the quaternary ammonium salts useful, are the tetraalkyl ammonium, e.g., tetraethyl or tetramethyl ammonium, methyltriethylammonium etc., heterocyclic and aralkyl ammonium salts, e.g., benzyltrimethylammonium, etc.

Various anions can be used with the foregoing and other cations, e.g. organic and inorganic anions, such as phosphates, halides, sulfates, sulfonates, alkylsulfate, etc. Aromatic sulfonates and similar anions e.g., p-toluenesulfonates, including those referred to as McKee salts, can be used, as can other hydrotropic salts, although the hydrotropic property may have no particular significance when employed with very low water content. it is desirable to have some material present which is capable of a discharge at the anode, and a small amount of a halide salt is generally suitable for this purpose. A small amount of olefinic hydrocarbon may be present to scavenge the resulting halogens. In general the salts disclosed in US. Pat. No. 3,390,066 of Manuel M. Baizer as suitable for hydrodimerization of certain allyl compounds, can also be employed in the present process, although the solubility considerations for solutions in water there discussed are not really essential to the present process. The concentration of salts, when used, can vary widely, e.g. from 0.5 to 50% or more by weight of the electrolysis medium, but suitableconcentrations will often be in the range of l to 15% by weight, or on a molar basis, often in the range of 0.1 to l molar. If it is desired to have all the components in solution, the amount of salt utilized will than be no greater than will dissolve in the electrolysis medium.

In some cases under some conditions, there may be advantages in using simple salts, such as lithium salts, and results may be comparable to or better than those obtainable with more complex salts. However, for general applicability and suitability at strongly negative discharge conditions, quaternary ammonium salts, or salts which discharge at more negative potential than 2.2 cathodic volts versus the saturated calomel electrode, are preferred. The term quaternary ammonium is used herein in its generally recognized meaning of a cation having four organo radicals substituted on nitrogen.

Various current densities can be employed in the present process. It will be desirable to employ high current densities in order to achieve high use of electrolysis cell capacity, and therefore for production purposes it will generally be desirable to use as high a denisty as feasible, taking into consideration sources and cost of electrical current, resistance of the electrolysis medium, heat dissipation, effect upon yields, etc. Over broad ranges of current density, the density will not greatly affect the yield. While very low densities are operable, suitable ranges for efficient operation will gen erally be in ranges from a few amperes/square decimeter of cathode surface, up to 10 or or more amperes/square decimeter. It is often advantageous to select the current with proper relationship to the olefin addition rate to react the olefin at the same rate as added and thus to maintain a desired cathode potential.

The present electrolysis can be conducted in the various types of electroylsis cells known to the art. In general such cells comprise a container made of material capable of resisting action of electrolytes, e.g. glass or plastics, and a cathode and anode which are electrically connected to sources of electric current. The anode can be of any electrode material so long as it is relatively inert under the reaction conditions. Ordinarily the anode will have a little or no influence on the course of the electrolysis, and can be selected as as to minimize expense and any corrosion, or erosion problem. However, there is a possiblility of some interference from oxidiation reactions, and this can be minimized by use of anodes other than platinum or carbon, for example by use of stainless steel or lead. Any suitable material can be employed as the cathode, various metals, alloys, graphite, etc. being known to the art. However, the cathode materials can have some effect upon the ease and efficiency of the reaction. For example mercury, cadmium, lead and carbon cathodes are suitable. The half-wave discharge potential of olefinic compounds will vary with the electrode material, and ordinarily the electrolysis will be facilitated by employing electrodes in the lower ranges of discharge potentials. However, it should be noted that performance of the materials can be greatly affected by surface characteristics, alloying, or impurities, e.g. stainless steel gives different half-wave potentials than iron.

ln the present process, a divided cell will often be employed, i.e., some separator will prevent the free flow of reactants between cathode and anode. Generally the separator is some mechanical barrier which is relatively inert to the electrolyte materials, e.g., a fritted glass filter, glass cloth, asbestos, porous polyvinyl chloride, etc. An ion exchange membrane can also be employed. The desired reactions will occur in an undivided cell, and this could have advantages for industrial production in that electrial resistance across a cell-divider is eliminated.

When a divided cell is used, it will be possible to em-' ploy the same electrolysis medium on both the cathode and anode sides, or to employ different media. In some circumstances, it may be advisable to employ a different anolyte, for economy of materials, lower electrical resistance, etc.

The electrolysis cell employed in the procedural Example herein, is primarily for laboratory demonstration purposes. Production cells are usually designed with a view to the economics of the process, and characteristically have large electrode surfaces, and short dis tances between electrodes. The present process is suited to either batch or continuous operations. Continuous operations can involve recirculation of a flowing electrolyte stream, or streams between electrodes, with continuous or intermittent sampling of the stream for product removal. Similarly, additional reactants can be added continuously or intermittently, and salt or other electrolyte components can be augmented, replenished, or removed as appropriate. In some cases it is advantageous to add the olefinic reactant at the rate at which it reacts and to have only a low concentration of such reactant present at any time, i.e., to have a high conversion of the olefinic reactant. Additional description of a suitable cell for continuous operation is set forth in US. Pat. No. 3,193,480 of Manuel M. Baizer et al.

The products obtained in the present process can be recovered by a variety of procedures. A chromatographic analysis has been largely used for convenient separation and identification. However, for production purposes, a separation by distillation, extraction, or a combination of such procedures will probably be employed. Distillation can be employed if there is sufficient difference in boiling points of the solvents, reactants, and ester products. Most of the simple esters can be distilled without any extensive thermal decomposition. Most of the esters will tend to be soluble in organic phases, rather than aqueous phases, and extraction with organic solvents, such as n-hexanes or diethyl ether are often suitable. Methylene chloride can similarly be used. Treatment with acids or bases can also be used in separations, with due care being taken to avoid saponification of the ester, and noting that the ester will generally be in the organic phase, while salts of the acids may be in the aqueous phase. Olefinic reactant can be distilled from the catholyte and recycled to the electrolysis in continuous procedures.

sistance and the electrical current drawn. If desired, I

cooling can be effected by permitting a component to reflux through a cooling condenser. Pressure can be employed to permit electrolysis at higher temperature with volatile reactants, but unnecessary employment of pressure is usually undesirable from an economic standpoint.

The present process involves a carboxylation reaction and therefore requires a source of the group, and carbon dioxide admirably serves this purpose. The carbon dioxide can be supplied at atmospheric pressure or at higher pressures, e.g., 50 or atmospheres or more of carbon dioxide. Other sources can also be used, such as alkali metal carbonates, for example sodium bicarbonate, or various other materials eqivalent to or a source of carbon dioxide or carbonic acid. The present invention comtemplates reactions occurring in the presence of carbon dioxide regardless of its source. In utilizing the carbon dioxide under ambient conditions, there is no need to rigidly exclude other gases from the reaction, and when operating at atmospheric pressure some of the pressure may be due to the partial pressure of other gases present.

The following Example is illustrative of the invention.

EXAMPLE A typical H-cell was employed in which cathode and anode compartments were separted by a medium porosity glass frit. A mercury cathode (38 cm surface area) and platinum anode were employed. As the catholyte medium, initially a ml. electrolyte solution was employed, which was a 0.1 to 0.2 molar solution of tetraethylammonium p-toluenesulfonate in acetonitrile, and the olefinic reactant was added thereto. Dry carbon dioxide was continuously bubbled into the catholyte at atmospheric pressure during the electrolysis. As the olefinic reactant, methyl trans-Bmethoxyacrylate was added at the rate of 0.74 gram/hour, which was sufficient to maintain a constant current at the applied potential. The current during the 6.5 hour electrolysis was 0.3 ampere and the temperature of the catholyte was about 18C. The catholyte after electrolysis was treated with 20 grams methyl iodide stirred overnight, evaported to dryness, the residue extracted with ether, the extract filtered and evaporated to leave 5.6 grams of material. Some oxalates and other materials were removed by distillation atreduced pressure to leave 1 gram of material, which was resolved on a florinated silicone column at 100 to 200C. at 10 per minute. About 60% of the material had a retention time of about 4.5 minutes. Mass spectrometry was utilized to determine the structureas having methoxy and carbomethoxyl substitutents on the same carbon atom, in-

dicating the structure as trimethyl l-methoxy-l,2,2- ethanetricarboxylate. The crrent efficiency to this product was calculated as 9.7%. h

The compound can suitably be used as a detergent builder. Related ester products can be prepared by using other esters of alkoxy acrylic acid as the reactant, and utilizing the corresponding organic iodides for the esterification step, for example electrolyzing ethyl ethoxyacrylate under the same reaction conditions as used in the Example, and utilizing ethyl iodide for esterification. If desired,,mixed esters can be obtained by electrolyzing, for example, ethyl ethoxymethacrylate and esterifying with methyl iodide. The foregoing products can be employed as detergent builders and for other purposes in the same manner as the trimethyl product, and various other lower alkyl alkoxy esters are similarly useful. Similarly, other a,B-olefinic nitriles, esters and amides with the indicated hetero-atom containing groups can be utilized in the illustrated procedure. Thus any of the specific olefins disclosed herein can be utilized, preferably in concentrations no more than ten times that of the carbon dioxide on a molar basis to obtain corresponding products. For example, ,B-ethoxyacrylonitrile can produce methyl ac-ethoxy B-cyanopropionate. The presence ofether groups in the products is of particular interest as such groups are generally subject to biodegradation and this is a much sought after property. The present invention makes it feasible to incorporate one or a multiplicity of ether or other heteroatoms in such molecules. The products with other hetero atoms will be useful for the purposes set forth herein because of the carboxyl functionality, and the hetero atoms may contribute additional useful properties in manner similar to the other groups.

The carboxylated products produced in the present process can be readily interconverted from acid to salt or ester form, etc. The carboxyl functionability makes the products suitable for various purposes in known manner as intermediates. Many of the products are known compounds of known uses. The products in various forms, are suitable as detergent builders and can be modified for such purpose by formation of various salts, or by formation of various esters or polyesters or ethers through reaction with glycols or other alcohols. Resinous polyesters suitable for coating or fiber forming uses, can also be produced by usual ester forming reaction of the carboxyl products, in either ester or free acid form, with polyhydroxy compounds. with difunctional products being appropriate for production of linear polymers, while tri-or' greater functionability is useful where cross-linking is desired.

What is claimed is: a l. The method of electrolytic dicarboxylation of alpha, beta-olefinic nitriles, esters, and carboxamides, having an organic group selected from oxy, thio, phosphino and amino groups attached to one of the olefinic carbon atoms, which comprises effecting electrolytic reduction at a cathode selected from the group consisting of mercury, cadmium, lead and carbon by electrolysis in an electrolysis medium comprising such olefinic compound, an apratic solvent, supporting electrolyte and carbon dioxide, and recovering a dicarboxylated product of such olefinic compound.

2. The method of claim 1 in which the olefinic compound is a ,B-alkoxy, a, ,B-olefinic nitrile, ester or amide.

3. The method of claim 1 in which the olefinic compound is represented by the formula and X is selected from cyano, carboxyl, or carboxamido groups, Y is selected from alkoxy, alkylthio, arylthio, alkylamino, arylamino, alkylphosphino and arylphospino groups, and the R's are individually selected from hydrogen, monovalent aliphatic radicals, or X.

4. The method of claim 1 in which a quaternary ammonium salt electrolyte is used.

5. The method of claim 1 in which the concentration of olefinic reactant is no more than 10 times that of the carbon dioxide on a molar basis.

6. The method of claim 1 in which the olefinic reactant is an alkyl B-alkoxyacrylate.

7. The method of claim 1 in which methyl B-methoxyacrylate is converted to trimethyl l-methoxy-l,2,2- ethane tricarboxylate.

8. The method of claim 1 in which the cathode is lead and the solvent is acetonitrile.

9. The method of claim 1 in which the cathode is lead and the solvent is dimethylformamide.

10. The method of claim 1 in which the electrolysis is carried out at the discharge potential of the olefinic 

2. The method of claim 1 in which the olefinic compound is a Beta -alkoxy, Beta -olefinic nitrile, ester or amide.
 3. The method of claim 1 in which the olefinic compound is represented by the formula YCR CRX and X is selected from cyano, carboxyl, or carboxamido groups, Y is selected from alkoxy, alkylthio, arylthio, alkylamino, arylamino, alkylphosphino and arylphospino groups, and the R''s are individually selected from hydrogen, monovalent aliphatic radiCals, or X.
 4. The method of claim 1 in which a quaternary ammonium salt electrolyte is used.
 5. The method of claim 1 in which the concentration of olefinic reactant is no more than 10 times that of the carbon dioxide on a molar basis.
 6. The method of claim 1 in which the olefinic reactant is an alkyl Beta -alkoxyacrylate.
 7. The method of claim 1 in which methyl Beta -methoxyacrylate is converted to trimethyl 1-methoxy-1,2,2-ethane tricarboxylate.
 8. The method of claim 1 in which the cathode is lead and the solvent is acetonitrile.
 9. The method of claim 1 in which the cathode is lead and the solvent is dimethylformamide.
 10. The method of claim 1 in which the electrolysis is carried out at the discharge potential of the olefinic compound. 